An automated system for sorting dissimilar materials, and in particular for sorting plastics from other materials and for sorting different types of plastics from one another comprises, depending upon the embodiment, combinations of a sizing mechanism, a friction separation, an air separator, a magnetic separator, a dielectric sensor sortation bed, shaker screening, a ballistic separator, an inductive sensor sortation system and a float/sink tank. The dielectric sensor sortation system may be either analog or digital, depending upon the particular implementation. One or more float/sink tanks can be used, depending upon the embodiment, each with a media of a different specific gravity. The media may be water, or water plus a compound such as calcium chloride. In addition, multiples of the same general type of module can be used for particular configurations. A heavy media system or a sand float process can be used either alternatively or additionally.